"In low-throughput situations, sample tracking and record keeping can often be handled adequately in a manual fashion," notes the patent. "But with the advent of medium- to high-throughput sample processing, it has become more challenging to track each sample and maintain information on it for ready accessing."
Applera's patent (No 6,726,820) covers both the microdevices themselves - used on a range of sample containers such as a plate, chip or slide - and the technology used to read the device. This sample processing station could be used alongside a range of experimental techniques, including electrophoresis, polymerase chain reaction (PCR), genetic analysis etc.
With regard to the type of information that could be carried on such a device, Applera notes that this could include the sample identification number and history and a person's notes pertaining to a sample, amongst other things. It could also carry instructions that can be read by an apparatus for acting on samples, and the apparatus could then write the results to the memory of the microdevice.
A microdevice-based system based on the technologies described in the patent should provide a more robust alternative to barcodes, which are already widely used for sample management.
"Providing sample containers with bar codes has provided some advantages in sample tracking," according to Applera. However, as a practical matter, a bar code per se carries very little information, simply being an identifier. Further, there is a lower limit on the size of container with which a bar code can be used."
This becomes more significant as the number of samples used in high-throughput experimentation swells, just and the volumes of reagents and substrates that are used shrink.
In addition, a barcode itself - or indeed any other type of 2D code - is static information. That is, once it is printed and placed on a sample container, it cannot be readily changed.
"Sample tracking and information maintenance will become even more challenging as the industry moves toward microdevice, very high-throughput formats," said Applera, noting that its solution overcomes these limitations.
Take-up of this type of technology should also be helped by the move to open platform systems among laboratory information management system (LIMS) manufacturers.